The present invention relates to the production of superabrasive cutting blanks and more particularly to enhancing chip control by such blanks.
In turning operations on metals, a ribbon-like strip of metal is removed from the workpiece. The strip or ribbon is cut off from the workpiece at the edge of the cutting insert. Control of this ribbon of metal is important for a number of reasons. In this regard, such strips of material also result from drilling operations, for example in mining applications. Chip control in these non-metal operations also is important.
If the strip taken off from the workpiece by the cutting insert is not broken up, the strip can feed into the tool holder or other portions of the machine and cause difficulties, e.g. damaging parts of the tool holder or obstructing visibility of the working area. Further, long ribbons are difficult to handle and can represent a safety hazard to the machine operator in metal turning operations.
Preferably, the strip taken off of the workpiece is caused to break-up into short pieces or chips which will readily fall away from the machining region into a receiving space or containers so that the chips are contained and can be removed from the machine tool. In drilling operations, chip removal is important so that drilling efficiency and tool insert damage does not result.
In metal turning operations utilizing cemented tungsten carbide inserts, chip breaker grooves or lands have been proposed in the art. Such chip breaker patterns on the carbide blank are provided during the blank molding operation. In this regard, reference is made to the following: U.S. Pat. Nos. 3,733,664, 3,973,307, 4,087,193, and 4,214,845, and British patent applications Nos. 51899 and 51968.
What is lacking in the art is the ability to provide chip breaker patterns on the surface of superabrasive compacts typified by polycrystalline diamond and CBN compacts.